There are not that many types of User Applications around the Internet if you start to categorize them properly. Sure, there are different domains that have different topics, use variety of technologies on the backend or on the front end. The front end may be even totally non-comparable. There are coffee machines, smart speakers, watches, phones, computers, refrigerators. At the end of the day, from the data model and architectural approach – many applications are actually very similar. What is differentiating them are the labels in stuff.
Simple Static Web Sites
They are for me – applications that do not need server for their functionality after the initial loading of the resources. They could be dynamic, shiny, functional. Applications like that are games or that only access offline storage like the local storage or the index DB.
Sites with Authentication and some private Content
A lot of applications are just resources that are accessed after Authentication. The users and the data does not interact with any other third party or between (the users and ) each other. These may be notes, to-dos, photos, budgets, and more.
They’re Similar to the private applications but they also have access roles. Only the authenticated users have the write permission on the records. The difference with CMS is that the view or read access is granted to all users – even to the not authenticated.
Online Stores are CMSes with several additional features that ease sells and purchases. From the Authenticated side – there is a CMS for products & admin interface for order processing. From the client/consumer side – one could manage a shopping cart. A good e-store also has integration with payment integrations like PayPal, Credit/Debit Card gateways, even cryptocurrency transferring.
Social Media Networks
The Social Networks are CMSes for logged users. Added to that – they offer some additional functionality over a news feed. People may like, share, do some other specific action or some of the new and popular reactions on the content. They could also be commented on multiple levels. The comments are a simple tree structure – a data model with reference to itself that could be of variety of types – pictures, videos, simple texts.
Messengers are like private CMSes that fade away with the new messages. The structure of the messages are mostly flat structure – only one new level of hierarchy. Some variations have 1:1, one to many, many to one communication channels. The great feature that make them useful are Push Notifications.
Marketplaces are CMSes but they have two groups with their roles. The users in these systems may be producers and consumers. Many times the consumers may be also – producers. Such example web sites are the marketplaces like OLX that offer both the sell and the buy feature.